<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="bootstrap-5.3.0-dist/css/bootstrap.min.css">
    <style>
      .content {
        width: 10rem;
        height: 8rem;
        border: 1px solid black;
      }
      .box {
        border: 1px dashed black;
      }
    </style>
  </head>
  <body>
    <div class="content">
      <div class="box m-sm-2 m-md-4 p-sm-2 p-md-4">设置内外边距</div>
    </div>
  </body>
</html>
